This invention relates to document transport apparatus, and more particularly an improved light sensor device for sensing sheets or documents along a track.
In certain document processing systems it is necessary to load documents into document transport apparatus such that the documents are aligned in precise manner to facilitate subsequent reading of information contained on the documents and/or printing of information onto the documents. Such document loading apparatus, for example, is useful with transports for processing bank checks and merchant drafts, and for processing payments remitted by purchasers of goods and services.
In remittance processing systems, in particular, the loader device should be capable of rapidly and conveniently loading documents of various sizes and thicknesses, and of controllably aligning and advancing such documents into a main transport for processing. A typical transaction involved in remittance processing includes at least one check in payment of a customer bill or invoice along with a remittance coupon which is normally a returned portion of the invoice. Each of these documents contain machine readable data encoded thereon; the remittance coupon will normally include the customer's account number and the invoice amount, while the check will normally include the maker's bank and checking account numbers. The various functions performed by a remittance processing system may include the reading and storing of the machine readable data from both documents and/or the recording of video images of the documents including the machine readable data. From such data and other information obtained from the documents, the checks may be further imprinted with coded data representing the dollar amount of the check, the documents may be sorted, and various compilations of data may be prepared for further utilization.
Remittance processing systems include loader devices which permit documents to be vertically fed or hand-dropped by an operator into the loader, and which permit documents to be laterally fed into the loader by an automatic feeder apparatus. In either mode, the loader aligns or registers the bottom edge of the document along a registration surface of a track and then advances the document along the track. Such loaders permit the aligned document to be temporarily retained, or gated, prior to entering the system's main transport, by means for controllably blocking the loader's exit with a physical gate. When documents are automatically fed, further controllable means is normally provided by physically gating the document prior to its laterally entering the loader.
As the transports of remittance processing systems and automatic feeder apparatus increase in document throughput speed, the ability of prior art loaders to reliably keep pace becomes more difficult. Further, prior art loaders cannot generally accommodate documents of various thicknesses without adjustment being made to the loader, or documents of unusually narrow widths.